upload gets stuck when "parallel" on Windows

[yarikoptic]

this might be a duplicate of a ghost (I can't see it - says doesn't exit) issue #1321 by @ZhuJiaBCM (also according to github - non existing account for me but does provide hyperlink and details with name and location to confirm my sanity... filed a support issue). From an email correspondence:

As I told in slack, the upload succeeded by running :
'set DANDI_DEVEL=1', then 'dandi -l DEBUG upload --devel-debug'
The later trials for 'dandi -l DEBUG upload --J 1:1' and 'dandi -l DEBUG
upload --J 1:5' worked,
'dandi -l DEBUG upload --J 5:1' and 'dandi -l DEBUG upload --J 5:5' got
stuck.
As Yarik mentioned, the default uploading is 5 files at the same time-- 5
treads in parallel. So, I guess the reason I failed in previous uploading
is it can't deal multiple files at the same time.

and processes were stuck in pre-validating state. Might be something about caching by fscacher or locking... heh

[CodyCBakerPhD]

#1321 is now visible